AN ARABIDOPSIS GENE FAMILY ENCODING DRE CRT BINDING-PROTEINS INVOLVEDIN LOW-TEMPERATURE-RESPONSIVE GENE-EXPRESSION/

In higher plants, a cis-acting element, DRE/CRT, is involved in gene e xpression responsive to drought and low-temperature stress. To underst and signal transduction pathways from the cold stress signal to gene e xpression, we characterized a gene family for DRE/CRT-binding proteins DREB1A and CBF1 in Arabidopsis thaliana. DREB1A and CBF1 were shown t o be involved in low-temperature-responsive gene expression. We screen ed an Arabidopsis genomic DNA library with the cDNA fragment of DREB1A as a probe and isolated DREB1A and 2 related genes, DREB2B (= CBF1) a nd DREB1C. These were arrayed in the order B, A, C in an 8.7 kb region of Arabidopsis chromosome 4. Northern blot analysis using gene-specif ic probes showed that the 3DREB1 genes are induced mainly by cold stre ss but not by osmotic stress in leaves, roots, and stems. Several cons erved sequences were found in the promoter regions of all 3 genes. The beta-glucuronidase (GUS) reporter gene driven by the DREB1 promoters was induced at transcriptional level by low temperature in transgenic Arabidopsis plants. (C) 1998 Academic Press.